Page Banner

United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Impact of Gypsum on Crop Yield, Soil Chemical Properties, and the Solubility of Phosphorus

Location: National Soil Dynamics Laboratory

2008 Annual Report


1a.Objectives (from AD-416)
1. To evaluate the impact soil amendments have on dry matter production and nutrient recovery in a bermudagrass pasture. 2. To evaluate the impact soil amendments have on soil chemical properties, specifically pH, SO4, exchangeable Ca, Al, Mg, trace metals, and electrical conductivity. 3. To evaluate the impact soil amendments have on available P in the soil.


1b.Approach (from AD-416)
Transport of P from land application of manure poses a major treat to accelerated eutrophication in surface water. Thus, evaluation of best management practices to minimize the environment the impact of P loss from animal waste is needed. The use of soil amendments such as FGD-gypsum seems to be a low-cost viable option. FGD-gypsum is a byproduct of the gas desulfurization systems used to reduce air pollution in coal burning power plants. The supply of FGD-gypsum is projected to increase in coming years as air quality standards continue to increase. Agricultural producers and stakeholder could benefit from the waste byproduct. Thus, research is needed to assess the environmental and plant productivity effects of FGD gypsum application to soils. Thus, the objective of this study is to evaluate the environmental and plant productivity effects of FGD gypsum application to soils.


3.Progress Report

The use of flue gas desulfurization (FGD) scrubbers to remove sulfur from the flue gas of coal-burning power plants for electricity production yields gypsum as a byproduct of the scrubber process. FGD gypsum is used primarily by the wallboard and cement industries. However, installation of FGD scrubbers is expected to increase significantly in response to new and existing air pollution regulations, with a concomitant increase in FGD gypsum. The current markets are not expected to be able to utilize all of the FGD gypsum produced. Agricultural land could benefit from the use of FGD gypsum, as low cost alternative to commercial gypsum. Thus, research is needed to adequately assess the environmental and plant productivity effects of FGD gypsum application to soils. Therefore, a study was initiated to determine the rate of gypsum that is needed to increase plant yield in forage grasses and decrease the solubility of P, and to assess the use of FGD gypsum as an alternative low-cost effective amendment that provides the same benefits as commercial gypsum or better. The study was initiated on an established Bermudagrass field. Poultry litter was used as the source of fertilizer. Three different gypsum products (commercially available gypsum and FGD gypsum and FGD gypsum + fly ash from TVA) were applied at three different rates (2, 10, and 20 Mg ha-1). The goals of this study are to evaluate the impact FGD gypsum and FGD gypsum + fly ash in comparison with commercial gypsum and their effect on improving soil quality, soil fertility, and plant yield, while minimizing soluble P in the soil, resulting from poultry litter application. The information obtain in this study may aid the development better management practices for manure application that will minimize the loss of soluble P to the environment.


Last Modified: 12/25/2014
Footer Content Back to Top of Page